Process for synthesis of eliglustat and intermediate compounds thereof

ABSTRACT

The present invention relates to a process for synthesis of Eliglustat and intermediate compounds thereof. In particular, the present invention belongs to the field of synthesis of organic compounds, relates to a process for synthesis of Eliglustat and pharmaceutically acceptable salts thereof, and relates to the intermediate compounds used in the process and a process for preparation of the intermediate compounds. Compared with the existing synthetic processes, the process for preparing Eliglustat according to the present invention utilizes novel intermediates and steps for synthesis, has advantages of convenient operations, high yield, good purity of intermediates and desired product, and it is easy to apply the process in the industrial production.

TECHNICAL FIELD

The present invention relates to the field of synthesis of organic compounds. In particular, the present invention relates to a process for synthesis of Eliglustat and pharmaceutically acceptable salts thereof, and relates to the intermediate compounds in the process and a process for preparation of the intermediate compounds.

BACKGROUND ART

Gaucher disease is a disease of glucocerebroside accumulation caused by an autosomal recessive inheritance. The main reason is that deficiency of glucosylceramidase due to mutation of structural gene coding glucosylceramidase results in that glucocerebroside in macrophages cannot be further hydrolyzed and then is accumulated in the lysosome, leading to loss of the original function of the cells, thereby causing diseases in bone, bone marrow, spleen, liver and lung. Eliglustat is a glucosylceramidase inhibitor developed by Genzyme Co. as a subsidiary of Sanofi Co. The US Food and Drug Administration (FDA) approved Eliglustat as an orphan drug on Sep. 17, 2008 and formally approved it to enter the market on Aug. 19, 2014 (Trade name Cerdelga), used as a first-line oral drug for adult patients with Gaucher disease Type 1. According to an article in Journal of the American Medical Association, the oral treatment with Eliglustat resulted in significant improvements in spleen volume, hemoglobin level, liver volume and platelet count in patients with Gaucher disease Type 1.

The chemical name of Eliglustat is N-[(1R,2R)-2-(2,3-dihydro-benzo[1,4]dioxin-6-yl)-2-hydroxy-1-(pyrrolidinylmethyl) ethyl]octanamide with the structural formula below:

At present, the synthetic routes of Eliglustat mainly include:

Route I. U.S. Pat. No. 7,196,205B2 reported a synthetic route as follows:

Amidation reaction of Intermediate I with Intermediate II produces the desired product.

Intermediate A contains two chiral centers, and this intermediate is a key compound. The synthesis of this compound is the key step described in the patent. The patent specifically described the synthetic steps of intermediate A as follows.

The patent also introduces the method for preparation of intermediate B using N-hydroxysuccimide, and the intermediate B is more advantageous for carrying out the amidation reaction.

However, it is difficult to obtain the raw materials and adjuvants used in the route, the catalyst is expensive, the yield is low and it is difficult to apply the method to industry.

Route II. Patent CN104557851A reported a new synthetic route for synthesis of Eliglustat. The route used intermediate C and intermediate D as the key starting materials and utilized a chiral ligand to build two chiral centers.

The patent also introduces the synthetic methods of intermediate D:

Method 1:

The reaction of pyrrolidine with halo-nitroalkane is used to give intermediate D.

Method 2:

Reduction reaction is used to give intermediate D.

It is difficult to obtain the chiral ligand used in this route, the chiral ligand is expensive, and the key intermediate D is a nitrocompound which has risk of influencing safety in the course of its preparation and use.

Route III. Patent CN105646442A reported a method for preparation of Eliglustat. The route used intermediate G as starting material. After several reaction steps, the reaction with octanoyl chloride finally produces the desired product.

This route only relates to the synthesis from intermediate G to Eliglustat, but does not teach how to synthesize intermediate G. Furthermore, multiple steps of protection and deprotection result in low yield, increased cost and more complicated operations, thus are not advantageous for industrial production.

In order to overcome the defects in the above routes, the present invention provides a new process for synthesis of Eliglustat. The process has advantages of convenient operations, high yield, good purity of intermediates and desired product, and it is easy to apply the process in the industrial production.

CONTENTS OF THE INVENTION

Throughout the description, the following terms have the meanings as indicated below.

The term “alkyl”, whether it is used alone or in combination with other groups, represents a straight or branched monovalent, saturated hydrocarbon group consisting of carbon atom and hydrogen atom. The term “C₁₋₆ alkyl” represents straight or branched alkyl having 1-6 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, and n-hexyl.

“Halo” or “Halogen” represents fluoro, chloro, bromo or iodo.

“Haloalkyl” represents alkyl as defined above which is substituted with one or more halogens, e.g., trifluoromethyl.

The term “alkoxy”, whether it is used alone or in combination with other groups, represents group R′—O—, wherein R′ represents alkyl as defined above. “C₁₋₆ alkoxy” represents group R′—O—. wherein R′ represents C₁₋₆ alkyl as defined above.

“Haloalkoxy” represents alkoxy as defined above which is substituted with one or more halogens, e.g., trifluoromethoxy.

“Aryl” represents monocyclic or fused bicyclic aromatic ring containing carbon atoms. “C₅₋₁₀ aryl” represents aryl having 5-10 carbon atoms. For example, C₅₋₁₀ aryl may be phenyl or naphthyl.

“Aralkyl” represents alkyl as defined above which is substituted with aryl as defined above.

“Aralkoxy” represents alkoxy as defined above which is substituted with aryl as defined above.

“Acyl” represents group —CO—R, wherein R is alkyl, aryl or aralkyl as defined above.

The alkyl or aryl as mentioned above, whether it is used as itself per se or used as a part of other groups such as aralkyl and aralkoxy, may be optionally substituted with one or more substituents. In the case of “substituted alkyl”, the substituents on alkyl are preferably selected from C₁₋₆ alkoxy, halo, aryl and nitro, more preferably selected from methoxy, ethoxy, halo, phenyl and nitro. In the case of “substituted aryl”, the substituents on aryl are preferably selected from C₁₋₆ alkyl, C₁₋₆ alkoxy, halo, aryl and nitro, more preferably selected from methyl, methoxy, ethoxy, halo, phenyl and nitro.

“hydroxy-protecting reagent” refers to the reagents which can react with the compounds with hydroxyl to afford hydroxy-protecting group on the hydroxy, said hydroxy-protecting group is selected from alkyl, haloalkyl, aralkyl, alkoxyalkyl, allyl, acyl, or silyl protective group, such as t-BuMe₂Si, t-BuPh₂Si, (i-Pr)₃Si, Et₃Si, Me₃Si, allyl, 2-tetrahydropyranyl, methoxymethyl, formyl, acetyl, benzyl or —CH₂Ar, wherein Ar is unsubstituted or substituted aryl, such as p-methoxyphenyl or halogen-substituted phenyl. Those conventional hydroxy-protecting reagents which can afford hydroxy-protecting groups are well-known for a person skilled in the art, such as tert-butyldimethylsilyl chloride, trimethylsilyl chloride, benzoyl chloride, and the like.

In a first aspect, the present invention provides a process for preparation of Eligluslat and pharmaceutically acceptable salts thereof.

the process comprising the following steps:

(a-1) sulfonylation reaction of Compound V to give Compound VI,

wherein R₅ is hydrogen or hydroxy-protecting group, said hydroxy-protecting group is selected from alkyl, haloalkyl, aralkyl, alkoxyalkyl, allyl, acyl or silyl protective group, such as t-BuMe₂Si, t-BuPh₂Si, (i-Pr)₃Si, Me₃Si, Me₃Si, allyl, 2-tetrahydropyranyl, methoxymethyl, formyl, acetyl, benzyl or —CH₂Ar, wherein Ar is unsubstituted or substituted aryl, such as p-methoxyphenyl or halogen-substituted phenyl,

M is alkyl, aryl, substituted aryl or substituted alkyl,

(a-2) reacting Compound VI with pyrrolidine to give Compound VII,

(a-3) reducing Compound VII by catalytic hydrogenation with metal catalyst or reducing Compound VII with organophosphorus reagent, to give Compound VIII,

(a-4) amidation reaction of Compound VIII with Compound IX to give Compound X.

wherein R₆ is selected from hydroxy, halogen or succimidyloxy,

-   -   when R₅ is hydrogen, Compound X is Eliglustat,     -   or     -   when R₅ is hydroxy-protecting group, the following step is         further carried out:

(a-5) deprotecting Compound X to remove hydroxy-protecting group, to give Eliglustat

In a preferred embodiment, the R₅ is hydrogen or silyl protective group, such as t-BuMe₂Si, t-BuPh₂Si, (i-Pr)₃Si, Et₃Si, or Me₃Si.

In a preferred embodiment, the R₆ is chloro or succimidyloxy.

In the step (a-1), sulfonylation reaction can be carried out with sulfonyl halide, such as alkylsulfonyl chloride, arylsulfonyl chloride, substituted arylsulfonyl chloride or substituted alkylsulfonyl chloride, such as p-toluenesulfonyl chloride, phenylsulfonyl chloride, p-halophenylsulfonyl chloride, p-nitrophenylsulfonyl chloride, o-nitrophenylsulfonyl chloride or methylsulfonyl chloride. The reaction can be carried out without catalyst or with appropriate amount of acylation catalyst, and the catalyst used may be DMAP; the base used in the reaction may be organic base which is commonly used, such as pyridine, organic tertiary amines, such as triethylamine or diisopropylethylamine. The reaction solvent is organic aprotic solvent, such as dichloromethane, chloroform, methyltetrahydrofuran, tetrahydrofuran, pyridine, toluene, ethyl acetate, acetonitrile, DMF, DMA, or a mixture of any two or more of the solvents.

In the step (a-2), pyrrolidine is reacted with the sulfonate of formula VI. The reaction solvent is organic aprotic solvent, such as dichloromethane, chloroform, methyltetrahydrofuran, tetrahydrofuran, pyridine, toluene, ethyl acetate, acetonitrile, DMF, DMA, or a mixture of any two or more of the solvents.

In the step (a-3), the metal catalyst used in the hydrogenation is Pd catalyst or Ni catalyst, such as Pd/C, Pd(OH)₂, Pd(OAc)₂, PdCl₂, Pd, Raney nickel, Ni; the organophosphorus reagent used is preferably triphenylphosphine. The reaction solvent is selected from alcohols, esters or ethers, or a mixture of any two or more of the solvents.

In the step (a-4):

When R₆ is hydroxy, the reaction of Compound VIII with Compound IX is carried out under catalysis of coupling agent to give Compound X. The reaction solvent is organic aprotic solvent, such as dichloromethane, chloroform, methyltetrahydrofuran, tetrahydrofuran, pyridine, toluene, ethyl acetate, acetonitrile, DMF, DMA, or a mixture of any two or more of the solvents. The coupling agent is the conventional coupling agent for amidation, such as EDC, DCC, HOBt, oxalyl chloride, or a mixture of any two or more thereof.

When R₆ is chloro or succimidyloxy, amidation reaction of Compound VIII with Compound IX yields Compound X; the reaction may be carried out without catalyst or with appropriate amount of deacid reagent, and the deacid reagent used in the reaction can be conventional organic base, such as pyridine, organic tertiary amines, such as triethylamine or diisopropylethylamine. The reaction solvent is organic aprotic solvent, such as dichloromethane, chloroform, methyltetrahydrofuran, tetrahydrofuran, pyridine, toluene, ethyl acetate, acetonitrile, DMF, DMA, or a mixture of any two or more of the solvents.

In the step (a-5):

When R₅ is silyl protective group, the reaction of step a-5 is carried out in the presence of base, acid or a fluorine-containing salt, the base is selected from alkali metal or alkaline earth metal hydroxide or carbonate, such as NaOH, KOH, Na₂CO₃, or K₂CO₃, and the fluorine-containing salt is preferably tetrabutylammonium fluoride (TBAF). The solvent used in the reaction is protonic solvent, such as water, methanol, ethanol, isopropanol, or a mixture of any two or more thereof.

When R₅ is alkyl, haloalkyl, alkoxyalkyl or allyl protective group, the reaction of step a-5 is carried out in the presence of acid. The reaction is preferably carried out in the presence of strong acid, such as trifluoroacetic acid or hydrochloric acid.

When R₅ is aralkyl protective group, the reaction of step a-5 is carried out under catalytic hydrogenation with metal catalyst, and the metal catalyst used in the hydrogenation is Pd catalyst or Ni catalyst, such as Pd/C, Pd(OH)₂, Pd(OAc)₂, PdCl₂, Pd, Raney nickel, Ni; the organophosphorus reagent used is preferably triphenylphosphine. The reaction solvent is selected from alcohols, esters or ethers, or a mixture of any two or more of the solvents.

When R₅ is p-methoxybenzyl, the reaction of step a-5 may be carried out in the presence of oxidizing agent. The oxidizing agent is preferably DDQ or ammonium ceric nitrate.

When R₅ is acyl protective group, the reaction of step a-5 is carried out under the condition of conventional deprotection to remove the acyl. For example, the deprotection may be carried out by hydrolysis with hydrochloric acid or sodium hydroxide, or by ester exchange with sodium methoxide/methanol.

In a particularly preferred embodiment of the above process, R₅ is hydrogen, and the process only includes the above reaction steps (a-1), (a-2), (a-3) and (a-4).

In a second aspect, the present invention provides compound of formula V:

wherein R₅ is hydrogen or hydroxy-protecting group, said hydroxy-protecting group is selected from alkyl, haloalkyl, aralkyl, alkoxyalkyl, allyl, acyl or silyl protective group, such as t-BuMe₂Si, t-BuPh₂Si, (i-Pr)₃Si, Et₃Si, Me₃Si, allyl, 2-tetrahydropyranyl, methoxymethyl, formyl, acetyl, benzyl or —CH₂Ar, wherein Ar is unsubstituted or substituted aryl, such as p-methoxyphenyl or halogen-substituted phenyl.

In a preferred embodiment, the compound of formula V has the structure of formula XI:

In a third aspect, the present invention provides a process for preparation of the compound of formula V,

wherein R₅ is hydrogen or hydroxy-protecting group, said hydroxy-protecting group is selected from alkyl, haloalkyl, aralkyl, alkoxyalkyl, allyl, acyl or silyl protective group, such as t-BuMe₂Si, t-BuPh₂Si, (i-Pr)₃Si, Et₃Si, Me₃Si, allyl, 2-tetrahydropyranyl, methoxymethyl, formyl, acetyl, benzyl or —CH₂Ar, wherein Ar is unsubstituted or substituted aryl, such as p-methoxyphenyl or halogen-substituted phenyl,

-   -   the process comprising step (c-1) and step (c-3) and optional         step (c-2):

(c-1) coupling reaction of Compound I with Compound II in the presence of Lewis acid, deacid reagent and coordination agent, to give Compound III,

wherein each of R₁, R₂ and R₄, independent of each other, is selected from hydrogen, alkyl, aryl or aralkyl, such as phenyl, isopropyl or benzyl,

(c-2) optionally, reacting Compound III with hydroxy-protecting reagent in the presence of base to give Compound IV, wherein R₅ is hydroxy-protecting group as defined above

and

(c-3) preparing the compound of formula V by the following steps:

(c-3.1) reducing Compound III to obtain the Compound V wherein R₅ is hydrogen

or reducing Compound IV to obtain the Compound V wherein R₅ is hydroxy-protecting group as defined above

or

(c-3.2) oxidising Compound III to give Compound XI-1, and reducing Compound XI-1 to obtain the Compound V wherein R₅ is hydrogen (i.e, Compound XI)

or oxidizing Compound IV to give Compound V-1, and reducing Compound V-1 to obtain the Compound V wherein R₅ is hydroxy-protecting group as defined above

In a preferred embodiment, R₁ and R₂ are hydrogen and R₄ is phenyl or benzyl.

In another preferred embodiment, R₄ is isopropyl and R₁ and R₂ are phenyl.

When R₁ and R₂ are hydrogen and R₄ is phenyl. Compound I has the following structure (formula I-1):

Compound III has the following structure (formula III-1):

Compound IV has the following structure (formula IV-1):

When R₁ and R₂ are hydrogen and R₄ is benzyl, Compound I has the following structure (formula I-2):

Compound III has the following structure (formula III-2):

Compound IV has the following structure (formula IV-2):

When R₄ is isopropyl and R₁ and R₂ are phenyl. Compound I has the following structure (formula I-3):

Compound III has the following structure (formula III-3):

Compound IV has the following structure (formula IV-3):

In step c-1, the Lewis acid is preferably titanium tetrachloride or tin dichloride, the deacid reagent is organic base, such as triethylamine, pyridine, N,N-diisopropylethylamine, and the like, and the coordination agent is N-methyl pyrrolidone. The reaction temperature is −100° C. to 50° C. The reaction solvent is organic aprotic solvent, such as dichloromethane, chloroform, methyltetrahydrofuran, tetrahydrofuran, pyridine, toluene, ethyl acetate, acetonitrile, DMF, DMA, or a mixture of any two or more of the solvents.

In the optional step c-2, the reaction solvent is organic aprotic solvent, such as dichloromethane, chloroform, methyl tetrahydrofuran, tetrahydrofuran, pyridine, toluene, ethyl acetate, acetonitrile, DMF, DMA, or a mixture of any two or more of the solvents. The reaction temperature is −50° C. to 100° C.

In step e-3.1, the reducing agent is selected from sodium borohydride. potassium borohydride, boron trifluoride etherate, boranes, or a mixture of any two or more thereof. The reaction solvent is selected from polar solvent, such as tetrahydrofuran, methyl tetrahydrofuran, N,N-dimethyl formamide, N,N-dimethyl acetamide, water, methanol, ethanol, isopropanol, or a mixture of any two or more thereof.

In step c-3.2, the oxidizing agent is peroxide or a manganese-containing salt, such as hydrogen peroxide, tert-butyl hydroperoxide or potassium permanganate, or a mixture of any two or more thereof, the reaction can be carried out with or without catalysis of a base, and the base is selected from alkali metal or alkaline earth metal hydroxide or carbonate, such as LiOH, NaOH, KOH, Na₂CO₃, K₂CO₃. The solvent used in the oxidization reaction is protonic solvent, such as water, methanol, ethanol, isopropanol, or a mixture of any two or more thereof.

In step c-3.2, the reducing agent is selected from sodium borohydride, potassium borohydride, boron trifluoride etherate, boranes, or a mixture of any two or more thereof. The solvent used in the reduction reaction is selected from polar solvent, such as tetrahydrofuran, methyltetrahydrofuran, N,N-dimethyl formamide, N,N-dimethyl acetamide, water, methanol, ethanol, isopropanol, or a mixture of any two or more thereof.

In a fourth aspect, the present invention provides a process for preparation of the compound of formula IV.

wherein R₅ is hydroxy-protecting group, said hydroxy-protecting group is selected from alkyl, haloalkyl, aralkyl, alkoxyalkyl, allyl, acyl or silyl protective group, such as t-BuMe₂Si, t-BuPh₂Si, (i-Pr)₃Si, Et₃Si, Me₃Si, allyl, 2-tetrahydropyranyl, methoxymethyl, formyl, acetyl, benzyl or —CH₂Ar, wherein Ar is unsubstituted or substituted aryl, such as p-methoxyphenyl or halogen-substituted phenyl,

each of R₁, R₂ and R₄, independent of each other, is selected from hydrogen, alkyl, aryl or aralkyl, such as phenyl, isopropyl or benzyl,

the process comprising the following steps:

(c-1) coupling reaction of Compound I with Compound II in the presence of Lewis acid, deacid reagent and coordination agent, to give Compound III,

and

(c-2) reacting Compound III with hydroxy-protecting reagent in the presence of base to give Compound IV

In a preferred embodiment, R₁ and R₂ are hydrogen and R₄ is phenyl or benzyl.

In another preferred embodiment, R₄ is isopropyl and R₁ and R₂ are phenyl.

The reaction conditions of step c-1 and step c-2 in the process are described as above.

In a fifth aspect, the present invention provides a process for preparation of the compound of formula III,

wherein each of R₁, R₂ and R₄, independent of each other, is selected from hydrogen, alkyl, aryl or aralkyl, such as phenyl, isopropyl or benzyl.

the process comprising the following step:

(c-1) coupling reaction of Compound I with Compound II in the presence of Lewis acid, deacid reagent and coordination agent, to give Compound III.

In a preferred embodiment, R₁ and R₂ are hydrogen and R₄ is phenyl or benzyl.

In another preferred embodiment, R₄ is isopropyl and R₁ and R₂ are phenyl.

The reaction condition of step c-1 in the process is described as above.

In a sixth aspect, the present invention provides a process for preparation of Eliglustat and pharmaceutically acceptable salts thereof.

the process comprising the following steps:

(c-1) coupling reaction of Compound I with Compound II in the presence of Lewis acid, deacid reagent and coordination agent, to give Compound III.

wherein each of R₁, R₂ and R₄, independent of each other, is selected from hydrogen, alkyl, aryl or aralkyl, such as phenyl, isopropyl or benzyl,

(c-2) optionally, reacting Compound III with hydroxy-protecting reagent in the presence of base to give Compound IV,

wherein R₅ is hydroxy-protecting group, said hydroxy-protecting group is selected from alkyl, haloalkyl, aralkyl, alkoxyalkyl, allyl, acyl or silyl protective group, such as t-BuMe₂Si, t-BuPh₂Si, (i-Pr)₃Si, Et₃Si, Me₃Si, allyl, 2-tetrahydropyranyl, methoxymethyl, formyl, acetyl, benzyl or —CH₂Ar, wherein Ar is unsubstituted or substituted aryl, such is p-methoxyphenyl or halogen-substituted phenyl; and

(c-3) preparing the compound of formula V by the following steps:

(c-3.1) reducing Compound III to obtain the Compound V wherein R₅ is hydrogen

or

reducing Compound IV to obtain the Compound V wherein R₅ is hydroxy-protecting group as defined above

or

(c-3.2) oxidizing Compound III to give Compound XI-1, and reducing Compound XI-1 to obtain the Compound V wherein R₅ is hydrogen (i.e. Compound XI)

or oxidizing Compound IV to give Compound V-1, and reducing Compound V-1 to obtain the Compound V wherein R₅ is hydroxy-protecting group as defined above

and

(a-1) sulfonylation reaction of Compound V to give Compound VI,

(a-2) reacting Compound VI with pyrrolidine to give Compound VII,

(a-3) reducing Compound VII by catalytic hydrogenation with metal catalyst or reducing Compound VII with organophosphorus reagent, to give Compound VIII,

(a-4) amidation reaction of Compound VIII with Compound IX to give Compound X,

when R₅ is hydrogen. Compound X is Eliglustat,

or

when R₅ is hydroxy-protecting group, the following step is further carried out:

(a-5) deprotecting Compound X to remove hydroxy-protecting group, to give Eligluistat

wherein:

R₆ is selected from hydroxy, halogen or succimidyloxy,

M is alkyl, aryl, substituted aryl or substituted alkyl.

In a preferred embodiment, R₁ and R₂ are hydrogen and R₄ is phenyl or benzyl.

In another preferred embodiment, R₄ is isopropyl and R₁ and R₂ are phenyl.

When R₁ and R₂ are hydrogen and R₄ is phenyl, Compound I has the following structure (formula I-1):

Compound III has the following structure (formula III-1):

Compound IV has the following stricture (formula IV-1):

When R₁ and R₂ are hydrogen and R₄ is benzyl. Compound I has the following structure (formula I-2):

Compound III has the following structure (formula III-2):

Compound IV has the following structure (formula IV-2):

When R₁ and R₂ are phenyl and R₄ is isopropyl, Compound I has the following structure (formula I-3);

Compound III has the following structure (formula III-3):

Compound IV has the following structure (formula IV-3):

In another preferred embodiment, R₆ is chloro or succimidyloxy.

In another preferred embodiment, R₅ is hydrogen or silyl protective group.

According to a preferred embodiment of the process, in step c-1, the Lewis acid is preferably titanium tetrachloride or tin dichloride, the deacid reagent is organic base, such as triethylamine, pyridine, N,N-diisopropylethylamine, and the like, and the coordination agent is N-methyl pyrrolidone. The reaction temperature is −100° C. to 50° C. The reaction solvent is organic aprotic solvent, such as dichloromethane, chloroform, methyltetrahydrofuran, tetrahydrofuran, pyridine, toluene, ethyl acetate, acetonitrile, DMF, DMA, or a mixture of any two or more of the solvents.

In the optional step c-2, the reaction solvent is organic aprotic solvent, such as dichloromethane, chloroform, methyltetrahydrofuran, tetrahydrofuran, pyridine, toluene, ethyl acetate, acetonitrile, DMF, DMA, or a mixture of any two or more of the solvents. The reaction temperature is −50° C. to 100° C.

In step e-3.1, the reducing agent is selected from sodium borohydride, potassium borohydride, boron trifluoride etherate, boranes, or a mixture of any two or more thereof. The solvent in the reduction reaction is selected from polar solvent, such as tetrahydrofuran, methyltetrahydrofuran, N,N-dimethyl formamide, N,N-dimethyl acetamide, water, methanol, ethanol, isopropanol, or a mixture of any two or more thereof.

In step c-3.2, the oxidizing agent is peroxide or a manganese-containing salt, such as hydrogen peroxide, tert-butyl hydroperoxide or potassium permanganate, or a mixture of any two or more thereof, the reaction can be carried out with or without catalysis of a base, and the base is selected from alkali metal or alkaline earth metal hydroxide or carbonate, such as LiOH, NaOH, KOH, Na₂CO₃, K₂CO₃. The solvent used in the oxidization reaction is protonic solvent, such as water, methanol, ethanol, isopropanol, or a mixture of any two or more thereof.

In step c-3.2, the reducing agent is selected from sodium borohydride, potassium borohydride, boron trifluoride etherate, boranes, or a mixture of any two or more thereof. The solvent used in the reduction reaction is selected from polar solvent, such as tetrahydrofuran, methyltetrahydrofuran, N,N-dimethyl formamide, N,N-dimethyl acetamide, water, methanol, ethanol, isopropanol, or a mixture of any two or more thereof.

According to a further preferred embodiment of the process, in the step (a-1), sulfonylation reaction can be carried out with sulfonyl halide, such as alkylsulfonyl chloride, arylsulfonyl chloride, substituted arylsulfonyl chloride or substituted alkylsulfonyl chloride, such as p-toluenesulfonyl chloride, phenylsulfonyl chloride, p-halophenylsulfonyl chloride, p-nitrophenylsulfonyl chloride, o-nitrophenylsulfonyl chloride or methylsulfonyl chloride. The reaction can be carried out without catalyst or with appropriate amount of acylation catalyst, and the catalyst used may be DMAP; the base used in the reaction may be organic base which is commonly used, such as pyridine, organic tertiary amines, such as triethylamine or diisopropylethylamine. The reaction solvent is organic aprotic solvent, such as dichloromethane, chloroform, methyltetrahydrofuran, tetrahydrofuran, pyridine, toluene, ethyl acetate, acetonitrile, DMF, DMA, or a mixture of any two or more of the solvents.

In the step (a-2), pyrrolidine is reacted with the sulfonate of formula VI. The reaction solvent is organic aprotic solvent, such as dichloromethane, chloroform, methyltetrahydrofuran, tetrahydrofuran, pyridine, toluene, ethyl acetate, acetonitrile, DMF, DMA, or a mixture of any two or more of the solvents;

In the step (a-3), the metal catalyst used in the hydrogenation is Pd catalyst or Ni catalyst, such as Pd/C, Pd(OH)₂, Pd(OAc)₂, PdCl₂, Pd, Raney nickel, Ni; the organophosphorus reagent used is preferably triphenylphosphine. The reaction solvent is selected from alcohols, esters or ethers, or a mixture of any two or more of the solvents.

In the step (a-4):

When R₆ is hydroxy, the reaction of Compound VIII with Compound IX is carried out under catalysis of coupling agent to give Compound X. The reaction solvent is organic aprotic solvent, such as dichloromethane, chloroform, methyltetrahydrofuran, tetrahydrofuran, pyridine, toluene, ethyl acetate, acetonitrile, DMF, DMA, or a mixture of any two or more of the solvents. The coupling agent is the conventional coupling agent for amidation, such as EDC, DCC, HOBt, oxalyl chloride, or a mixture of any two or more thereof.

When R₆ is chloro or succimidyloxy, amidation reaction of Compound VIII with Compound IX yields Compound X; the reaction may be carried out without catalyst or with appropriate amount of deacid reagent, and the deacid reagent used in the reaction can be conventional organic base, such as pyridine, organic tertiary amines, such as triethylamine or diisopropylethylamine. The reaction solvent is organic aprotic solvent, such as dichloromethane, chloroform, methyltetrahydrofuran, tetrahydrofuran, pyridine, toluene, ethyl acetate, acetonitrile, DMF, DMA, or a mixture of any two or more of the solvents.

According to another preferred embodiment of the process, the reaction condition of step (a-5) is as follows:

When R₅ is silyl protective group, the reaction of step a-5 is carried out in the presence of base, acid or a fluorine-containing salt, preferably in the presence of a base or a fluorine-containing salt, the base is selected from alkali metal or alkaline earth metal hydroxide or carbonate, such as NaOH, KOH, Na₂CO₃, K₃CO₃, and the fluorine-containing salt is preferably tetrabutylammonium fluoride (TBAF). The solvent used in the reaction is protonic solvent, such as water, methanol, ethanol, isopropanol, or a mixture of any two or more thereof.

When R₅ is alkyl, haloalkyl, alkoxyalkyl or allyl protective group, the reaction of step a-5 is carried out in the presence of acid. The reaction is preferably carried out in the presence of strong acid, such as trifluoroacetic acid or hydrochloric acid.

When R₅ is aralkyl protective group, the reaction of step a-5 is carried out under catalytic hydrogenation with metal catalyst, and the metal catalyst used in the hydrogenation is Pd catalyst or Ni catalyst, such as Pd/C, Pd(OH)₂, Pd(OAc)₂, PdCl₂, Pd, Raney nickel, Ni. The organophosphorus reagent used is preferably triphenylphosphine. The reaction solvent is selected from alcohols, esters or ethers, or a mixture of any two or more of the solvents.

When R₅ is p-methoxybenzyl, the reaction of step a-5 may be carried out in the presence of oxidizing agent. The oxidizing agent is preferably DDQ or ammonium ceric nitrate.

When R₅ is acyl protective group, the reaction of step a-5 is carried out under the condition of conventional deprotection to remove the acyl. For example, the deprotection may be carried out by hydrolysis with hydrochloric acid or sodium hydroxide, or by ester exchange with sodium methoxide/methanol.

In a particularly preferred embodiment of the process, R₅ is hydrogen, and the process only includes the reaction steps c-1, c-3, a-1, a-2, a-3 and a-4.

In a seventh aspect, the present invention provides a process for preparation of Eliglustat and pharmaceutically acceptable salts thereof.

the process comprising the following steps;

(a-3) reducing Compound VII by catalytic hydrogenation with metal catalyst or reducing Compound VII with organophosphorus reagent, to give Compound VIII,

wherein R₅ is hydrogen or hydroxy-protecting group, said hydroxy-protecting group is selected from alkyl, haloalkyl, aralkyl, alkoxyalkyl, allyl, acyl or silyl protective group, such as t-BuMe₂Si, t-BuPh₂Si, (i-Pr)₃Si, Et₃Si, Me₃Si, allyl, 2-tetrahydropyranyl, methoxymethyl, formyl, acetyl, benzyl or —CH₂Ar, wherein Ar is unsubstituted or substituted aryl, such is p-methoxyphenyl or halogen-substituted phenyl,

(a-4) amidation reaction of Compound VIII with Compound IX to give Compound X.

wherein R₆ is selected from hydroxy, halogen or succimidyloxy,

when R₅ is hydrogen. Compound X is Eliglustat,

or

when R₅ is hydroxy-protecting group, the following step is further carried out:

(a-5) deprotecting Compound X to remove hydroxy-protecting group, to give Eliglustat

In a preferred embodiment, the R₅ is hydrogen or silyl protective group, such as t-BuMe₂Si, t-BuPh₂Si, (i-Pr)₃Si, or Et₃Si.

In another preferred embodiment, the R₆ is chloro or succimidyloxy.

In a further preferred embodiment, in the step (a-3), the metal catalyst used in the hydrogenation is Pd catalyst or Ni catalyst, such as Pd/C, Pd(OH)₂, Pd(OAc)₂, PdCl₂, Pd, Raney nickel, Ni; the organophosphorus reagent used is preferably triphenylphosphine. The reaction solvent is selected from alcohols, esters or ethers, or a mixture of any two or more of the solvents.

In the step (a-4):

When R₆ is hydroxy, the reaction of Compound VIII with Compound IX is carried out under catalysis of coupling agent to give Compound X. The reaction solvent is organic aprotic solvent, such as dichloromethane, chloroform, methyltetrahydrofuran, tetrahydrofuran, pyridine, toluene, ethyl acetate, acetonitrile, DMF, DMA, or a mixture of any two or more of the solvents. The coupling agent is the conventional coupling agent for amidation, such as EDC, DCC, HOBt, oxalyl chloride, or a mixture of any two or more thereof.

When R₆ is chloro or succimidyloxy, amidation reaction of Compound VIII with Compound IX yields Compound X. The reaction may be carried out without catalyst or with appropriate amount of deacid reagent, and the deacid reagent used in the reaction can be conventional organic base, such as pyridine, organic tertiary amines, such as triethylamine or diisopropylethylamine. The reaction solvent is organic aprotic solvent, such as dichloromethane, chloroform, methyltetrahydrofuran, tetrahydrofuran, pyridine, toluene, ethyl acetate, acetonitrile, DMF, DMA, or a mixture of any two or more of the solvents.

In another preferred embodiment, the reaction condition of step (a-5) is as follows:

When R₅ is silyl protective group, the reaction of step a-5 is carried out in the presence of base, acid or a fluorine-containing salt, preferably in the presence of a base or a fluorine-containing salt, the base is selected from alkali metal or alkaline earth metal hydroxide or carbonate, such as NaOH, KOH, Na₂CO₃, K₂CO₃, and the fluorine-containing salt is preferably tetrabutylammonium fluoride (TBAF). The solvent used in the reaction is protonic solvent, such as water, methanol, ethanol, isopropanol, or a mixture of any two or more thereof.

When R₅ is alkyl, haloalkyl, alkoxyalkyl or allyl protective group, the reaction of step a-5 is carried out in the presence of acid. The reaction is preferably carried out in the presence of strong acid, such as trifluoroacetic acid or hydrochloric acid;

When R₅ is aralkyl protective group, the reaction of step a-5 is carried out under catalytic hydrogenation with metal catalyst, and the metal catalyst used in the hydrogenation is Pd catalyst or Ni catalyst, such as Pd/C, Pd(OH)₂, Pd(OAc)₂, PdCl₂, Pd, Raney nickel, Ni; the organophosphorus reagent used is preferably triphenylphosphine. The reaction solvent is selected from alcohols, esters or ethers, or a mixture of any two or more of the solvents.

When R₅ is p-methoxybenzyl, the reaction of step a-5 may be carried out in the presence of oxidizing agent. The oxidizing agent is preferably DDQ or ammonium ceric nitrate.

When R₅ is acyl protective group, the reaction of step a-5 is carried out under the condition of conventional deprotection to remove the acyl. For example, the deprotection may be carried out by hydrolysis with hydrochloric acid or sodium hydroxide, or by ester exchange with sodium methoxide/methanol.

In a particularly preferred embodiment, R₅ is hydrogen, and the process only includes the above reaction steps (a-3) and (a-4).

In an eighth aspect, the present invention provides the compound of formula VII:

wherein R₅ is hydrogen or hydroxy-protecting group, said hydroxy-protecting group is selected from alkyl, haloalkyl, aralkyl, alkoxyalkyl, allyl, acyl or silyl protective group, such as t-BuMe₂Si, t-BuPh₂Si, (i-Pr)₃Si, Et₃Si, Me₃Si, allyl, 2-tetrahydropyranyl, methoxymethyl, formyl, acetyl, benzyl or —CH₂Ar, wherein Ar is unsubstituted or substituted aryl, such as p-methoxyphenyl or halogen-substituted phenyl.

In a preferred embodiment, the compound of formula VII has the structure of formula XII

In a ninth aspect, the present invention provides a process for preparation of the compound of formula VII,

wherein R₅ is hydrogen or hydroxy-protecting group; said hydroxy-protecting group is selected from alkyl, haloalkyl, aralkyl, alkoxyalkyl, allyl, acyl or silyl protective group, such as t-BuMe₂Si, t-BuPh₂Si, (i-Pr)₃Si, Et₃Si, Me₃Si, allyl, 2-tetrahydropyranyl, methoxymethyl, formyl, acetyl, benzyl or —CH₂Ar, wherein Ar is unsubstituted or substituted aryl, such as p-methoxyphenyl or halogen-substituted phenyl.

the process comprising the following steps:

(a-1) sulfonylation reaction of Compound V to give Compound VI,

wherein M is alkyl, aryl, substituted aryl or substituted alkyl,

(a-2) reacting Compound VI with pyrrolidine to give Compound VII,

In a further preferred embodiment, the present invention provides a process for preparation of the compound of formula VII, comprising the following steps:

(c-1) coupling reaction of Compound I with Compound II in the presence of Lewis acid, deacid reagent and coordination agent, to give Compound III.

wherein each of R₁, R₂ and R₄, independent of each other, is selected from hydrogen, alkyl, aryl or aralkyl, such as phenyl, isopropyl or benzyl.

(c-2) optionally, reacting Compound III with hydroxy-protecting reagent in the presence of base to give Compound IV,

wherein R₅ is hydroxy-protecting group, said hydroxy-protecting group is selected from alkyl, haloalkyl, aralkyl, alkoxyalkyl, ally), acyl or silyl protective group, such as t-BuMe₂Si, t-BuPh₂Si, (i-Pr)₃Si, Et₃Si, Me₃Si, allyl, 2-tetrahydropyranyl, methoxymethyl, formyl, acetyl, benzyl or —CH₂Ar, wherein Ar is unsubstituted or substituted aryl, such is p-methoxyphenyl or halogen-substituted phenyl; and

(c-3) preparing the compound of formula V by the following steps:

(c-3.1) reducing Compound III to obtain the Compound V wherein R₅ is hydrogen

or

reducing Compound IV to obtain the Compound V wherein R₅ is hydroxy-protecting group as defined above

or

(c-3.2) oxidizing Compound III to give Compound XI-1, and reducing Compound XI-1 to obtain the Compound V wherein R₅ is hydrogen (i.e, Compound XI)

or

oxidizing Compound IV to give Compound V-1, and reducing Compound V-1 to obtain the Compound V wherein R₅ is hydroxy-protecting group as defined above

and

(a-1) sulfonylation reaction of Compound V to give Compound VI,

wherein M is alkyl, aryl, substituted aryl or substituted alkyl,

(a-2) reacting Compound VI with pyrrolidine to give Compound VII.

In a preferred embodiment, R₁ and R₂ are hydrogen and R₄ is phenyl or benzyl.

In another preferred embodiment, R₄ is isopropyl and R₁ and R₂ are phenyl.

In another preferred embodiment, R₅ is silyl protective group, such as t-BuMe₂Si, t-BuPh₂Si, (i-Pr)₃Si, or Et₃Si.

In a particularly preferred embodiment, R₅ is hydrogen, and the process only includes the reaction steps c-1, c-3, a-1 and a-2.

In the above process, the reaction conditions of steps c-1, c-2, c-3, a-1 and a-2 are described as above.

In a tenth aspect, the present invention provides crystal form A of (1R,2R)-2-amino-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-(pyrrolidin-1-yl)propane-1-ol monohydrate.

In an embodiment, the crystal form A has a X-ray powder diffraction pattern having the characteristic diffraction peaks at 2-theta angle (°): 17.5, 18.5, and 21.3.

In a preferred embodiment, the crystal form A has a X-ray powder diffraction pattern having the characteristic diffraction peaks at 2-theta angle (°); 17.5, 18.5. 19.9. 21.3, and 25.7.

In a further preferred embodiment, the crystal form A has a X-ray powder diffraction pattern having the characteristic diffraction peaks at 2-theta angle (°): 6.4, 11.4, 12.3, 17.5, 18.5, 19.9, 21.3, 22.9, 24.1, and 25.7.

In a more preferred embodiment, the crystal form A has a X-ray powder diffraction pattern as shown in FIG. 1.

In an embodiment, the crystal form A further has a thermogravimetric analysis (TGA) graph as shown in FIG. 3.

In on embodiment, the crystal form A further has a differential scanning calorimetry (DSC) graph as shown in FIG. 4.

Compared with the prior art, the process for preparation of Eliglustat and the key intermediates thereof provided by the present invention have advantages that it is easy to obtain the raw materials, the technology of the process is concise, is safe and is friendly to the environment. Moreover, the overall yield of the process is high, the product has good purity and the quality thereof is stable. Therefore, the present invention is useful for industrial production of the active pharmaceutical ingredient and for reduction of costs.

DESCRIPTION OF FIGURES

FIGS. 1 and 2 show the results of crystal form A of (1R,2R)-2-amino-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-(pyrrolidin-1-yl)propane-1-ol monohydrate in X-ray powder diffraction experiment.

FIG. 3 shows the result of crystal form A of (1R,2R)-2-amino-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-(pyrrolidin-1-yl)propane-1-ol monohydrate in thermogravimetric analysis (TGA) experiment.

FIG. 4 shows the result of crystal form A of (1R,2R)-2-amino-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-(pyrrolidin-1-yl)propane-1-ol monohydrate in differential scanning calorimetry (DSC) experiment.

EXAMPLES

The embodiments of the present invention will be further illustrated by the following examples. It should be understood that the following examples are provided to help further understand the present invention, not intended to limit the scope of the present invention in any manner.

Example 1 Preparation of 3-((2S,3R)-2-azido-3-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-hydroxypropanoyl)-4-phenyloxazolidin-2-one (Compound III-1)

10 mmol Compound I (wherein R₁ and R₂ are hydrogen, R₄ is phenyl) was dissolved in 100 ml dichloromethane, to which 12 mmol titanium tetrachloride was added dropwise at −78° C. After the mixture was stirred for 20 minutes, 15 mmol DIPEA was added. After the mixture was further stirred for 3 hours, 20 mmol N-methyl pyrrolidone was added. After the addition was completed, the reaction mixture was stirred for 30 minutes, and then 15 mmol

2,3-dihydrobenzo[b][1,4]dioxin-6-formaldehyde was added. After the addition was completed, the reaction mixture was maintained for 30 minutes. The reaction mixture was warmed to −20 to 30° C. and maintained for 2 hours at the temperature. Subsequently, saturated ammonium chloride aqueous solution was added to quench the reaction. The reaction mixture was extracted with dichloromethane twice. The organic phases were combined, washed with water, dried and concentrated to give 2.5 g of the product Compound III-1.

¹H NMR (400 MHz, CDCl₃) δ 7.40-7.26 (m, 5H), 6.99 (d, 1H), 6.91 (dd, 1H), 6.84 (d, 1H), 5.33 (dd, 1H), 5.18 (d, 1H), 5.15-5.13 (m, 1H), 4.59 (t, 1H), 4.25 (dd, 1H), 4.22 (s, 4H); ¹³C NMR (101 MHz, CDCl₃) δ 168.06, 153.28, 143.56, 143.49, 138.15, 132.56, 129.31, 129.20, 128.96, 126.05, 125.81, 119.24, 117.29, 115.32, 73.70, 70.65, 65.69, 64.35, 64.29, 57.90.; HR-MS (ESI) calcd for C₂₀H₁₉O₆N₄ (M+H)⁺: 411.1305, found 411.1312.

Example 2 Preparation (S)-3-((2S,3R)-2-azido-3-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-((trimethylsilyl)oxy)propanoyl)-4-phenyloxazolidin-2-one (Compound IV, wherein R₁ and R₂ are hydrogen, R₄ is phenyl, R₅ is trimethylsilyl)

10 mmol Compound III-1 (wherein R₁ and R₂ are hydrogen, R₄ is phenyl, R₅ is hydrogen) was dissolved in 200 ml dichloromethane, 10 which 12 mmol triethylamine was added al 0° C., and then 11 mmol trimethylsilyl chloride was added slowly. After the addition was completed, the reaction was maintained for 3 hours. The reaction mixture was quenched by adding water. Organic phase was dried and concentrated to give 4.3 g of Compound IV (wherein R₁ and R₂ are hydrogen, R₄ is phenyl, R₅ is trimethylsilyl).

¹H NMR (400 MHz, CDCl₃) δ 7.40-7.26 (m, 5H), 6.99 (d, 1H), 6.91 (dd, 1H), 6.83 (d, 1H), 5.24 (dd, 1H), 5.12 (d, 1H), 5.05 (d, 1H), 4.51 (t, 1H), 4.29-4.26 (m, 1H), 4.24 (s, 4H) , 0.07 (s, 9H); ¹³C NMR (101 MHz, CDCl₃) δ 167.86, 153.04, 143.34, 143.28, 138.11, 133.37, 129.30, 128.96, 125.78, 119.41, 116.98, 115.48, 75.30, 70.46, 66.08, 64.33, 64.30, 57.90, −0.29.; HR-MS (ESI) calcd for C₂₃H₂₇O₆N₄ (M+H)⁺: 483.1700, found 483.1717.

Example 3 Preparation of (S)-3-((2S,3R)-2-azido-3-(tert-butyldimethylsilyl)oxy)-3-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)propanoyl)-4-phenyloxazolidin-2-one (Compound IV, wherein R₁ and R₂ are hydrogen, R₄ is phenyl, R₅ is tert-butyldimethylsilyl)

10 mmol Compound III-1 (wherein R₁ and R₂ are hydrogen, R₄ is phenyl, R₅ is hydrogen) was dissolved in 200 ml dichloromethane, to which 12 mmol triethylamine was added at 0° C. and then 11 mmol tert-butyldimethylsilyl chloride was added slowly. After the addition was completed, the reaction was maintained for 3 hours. The reaction mixture was quenched by adding water. Organic phase was dried and concentrated to give 4.8 g of Compound IV (wherein R₁ and R₂ are hydrogen, R₄ is phenyl, R₅ is tert-butyldimethylsilyl).

¹H NMR (400 MHz, CDCl₃) δ 7.33-7.22 (m, 3H), 7.20-7.13 (m, 3H), 6.97 (d, 1H), 6.90 (d, 1H), 5.67 (ddt, 1H), 5.44 (dt, 1H), 4.47-4.40 (m, 2H), 4.28-4.17 (m, 4H), 4.10 (dd, 1H), 0.85 (s, 7H), −0.06 (s,4H); ¹³C NMR (101 MHz, CDCl₃) δ 171.90, 154.26. 143.28, 143.18, 137.83, 133.03, 128.25, 128.02, 127.45, 120.01, 114.41, 112.33, 76.73, 69.67, 63.72, 63.26, 63.20, 57.36, 25.61, 17.98, −4.77.; HR-MS (ESI) calcd for C₂₆H₃₂O₆N₄Si (M+H)⁺: 524.2091, found 524.2084.

Example 4 Preparation of (1R,2R)-2-azido-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)propane-1,3-diol (Compound XI)

7 mmol Compound III-1 was dissolved in a mixed solvent of 60 ml tetrahydrofuran and 10 ml water, to which 35 mmol sodium borohydride was added at 0° C. After the addition was completed, the reaction mixture was warmed to 25° C. and maintained for 3 hours at the temperature. After the reaction was completed, saturated mixture was extracted with ethyl acetate twice. The combined organic phases were washed with sodium bicarbonate solution, dried and concentrated to give 1.7 g of Compound XI.

¹H NMR (400 MHz, CDCl₃) δ 6.80-6.89 (m, 3H), 4.66 (d, J=6.8 Hz, 1H), 4.25 (m, 4H), 3.59-3.66 (m, 2H), 3.50-3.57 (m, 1H); ¹³C NMR (101 MHz, CDCl₃) δ 143.4, 133.5, 118.9, 117.7, 114.8, 74.1. 68.8, 64.0, 62.9; HR-MS (ESI)calcd for C₁₁H₁₄O₄N₃ (M+H)⁺: 252.0984, found 252.0988.

Example 5 Preparation of (2R,3R)-2-azido-3-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-((trimethylsilyl)oxy)propane-1-ol (Compound V, wherein R₅ is trimethylsilyl)

7 mmol Compound IV was dissolved in a mixed solvent of 60 ml tetrahydrofuran and 10 ml water, to which 35 mmol sodium borohydride was added at 0° C. After the addition was completed, the reaction mixture was warmed to 25° C. and maintained for 3 hours at the temperature. After the reaction was completed, saturated ammonium chloride solution was added to quench the reaction, and the reaction mixture was extracted with ethyl acetate twice. The combined organic phases were washed with sodium bicarbonate solution, dried and concentrated to give 2.5 g of Compound V. 1H NMR (400 MHz, CDCl₃) δ 7.09-7.00 (m, 2H), 6.88 (d, 1H), 4.73-4.68 (m, 1H), 4.28-4.17 (m, 4H), 3.62-3.53 (m, 1H), 3.42-3.31 (m, 2H), 2.68 (t, 1H), 0.16 (s, 7H).; ¹³C NMR (101 MHz, CDCl₃) δ 143.14, 143.12, 133.45, 119.83, 114.35, 112.44, 76.61, 68.15, 63.63, 63.60, 62.78, −0.26., HR-MS (ESI) calcd for C₁₄H₂₁O₄N₃Si (M+H)⁺: 323.1301, found 323.1321.

Example 6 Preparation of (2R,3R)-2-azido-3-((tert-butyldimethylsilyl)oxy)-3-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)propane-1-ol (Compound V, wherein R₅ is tert-butyldimethylsilyl)

7 mmol Compound IV was dissolved m a mixed solvent of 60 ml tetrahydrofuran and 10 ml water, to which 35 mmol sodium borohydride was added at 0° C. After the addition was completed, the reaction mixture was warmed to 25° C. and maintained for 3 hours at the temperature. After the reaction was completed, saturated ammonium chloride solution was added to quench the reaction, and the reaction mixture was extracted with ethyl acetate twice. The combined organic phases were washed with sodium bicarbonate solution, dried and concentrated to give 2.8 g of Compound V.

¹H NMR (400 MHz, CDCl₃) δ 7.09-7.02 (m, 2H), 6.88 (d, 1H), 4.85-4.80 (m, 1H), 4.28-4.17 (m, 4H), 3.69 (ddd, 1H), 3.60 (td, 1H), 3.50 (ddd, 1H), 2.68 (t, 1H), 0.84 (s, 6H), 0.02 (s, 4H).; ¹³C NMR (101 MHz, CDCl₃) δ 143.14, 143.14, 133.42, 119.89, 114.34, 112.39, 76.07, 68.60, 63.47, 63.44, 62.45, 25.59, 18.00, −4.76.; HR-MS (ESI) calcd for C₁₇H₂₇O₄N₃Si (M+H)⁺: 365.1771, found 365.1782.

Example 7 Preparation of (2R,2S)-2-azido-1(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-oxo-3-((S)-2-oxo-4-phenyloxazolidin-3-yl)propyl benzoate (Compound IV, wherein R₁ and R₂ are hydrogen, R₄ is phenyl, R₅ is benzoyl)

10 mmol Compound III-1 (wherein R₁ and R₂ are hydrogen, R₄ is phenyl, R₅ is hydrogen) was dissolved in 200 ml dichloromethane, to which 12 mmol triethylamine was added at 0° C., and then 11 mmol benzoyl chloride was added slowly. After the addition was completed, the reaction was maintained for 3 hours. The reaction mixture was quenched by adding water. Organic phase was dried and concentrated to give 4.9 g of Compound VI (wherein R₁ and R₂ are hydrogen, R₄ is phenyl, R₅ is benzoyl).

¹H NMR (400 MHz, CDCl₃) δ 8.17-8.07 (m, 2H), 7.62-7.56(m. 1H), 7.49-7.45(m, 2H), 7.40-7.33 (m, 3H), 7.30-7.27 (m, 2H), 7.13 (s, 1H), 7.06 (dd, 1H), 6.89 (d, 1H), 6.62 (d, 1H), 5.30-5.27 (m, 2H), 4.80 (t, 1H), 4.35 (dd, 1H), 4.25 (s, 4H); ¹³C NMR (101 MHz, CDCl₃) δ 167.55, 165.53, 153.74, 143.86, 143.58, 138.17, 134.56, 133.66, 130.56, 130.03, 129.28, 129.19, 128.96, 128.94, 128.88, 128.61, 125.91, 119.49, 117.54, 115.48, 74.88, 70.88, 68.31, 64.42, 64.34, 64.30, 58.11.; HR-MS (ESI) calcd for C₂₇H₂₃O₇N₄ (M+H)⁺: 515.1567, found 515.1558.

Example 8 Preparation of (1R,2R)-2-azido-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)propane-1,3-diol (Compound XI)

7 mmol Compound XI-1 was dissolved in 60 ml tetrahydrofuran, to which 14 mmol sodium borohydride and 8 mmol boron trifluoride etherate were added at 0° C. After the addition was completed, the reaction mixture was stirred for 3 hours while the temperature was maintained. After the reaction was completed, dilute hydrochloric acid was added to quench the reaction, and the reaction mixture was extracted with ethyl acetate twice. The combined organic phases were washed with sodium bicarbonate solution, dried and concentrated to give 1.4 g of Compound XI. ¹H NMR (400 MHz, CDCl₃)δ 6.80-6.89 (m, 3H), 4.66 (d, J=6.8 Hz, 1H), 4.25 (m, 4H), 3.59-3.66 (m, 2H), 3.50-3.57 (m, 1H); ¹³C NMR (101 MHz, CDCl₃) δ 143.4, 133.5, 118.9, 117.7, 114.8, 74.1, 68.8, 64.0, 62.9; HR-MS (ESI) calcd for C₁₁H₁₄O₄N₃ (M+H)⁺: 252.0984, found 252.0988.

Example 9 Preparation of (2R,3R)-2-azido-3-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-((trimethylsilyl)oxy)propyl 4-methylbenzenesulfonate (Compound VI, wherein R₅ is trimethylsilyl)

9 mmol Compound V (wherein R5 is trimethylsilyl) was dissolved in 200 ml dichloromethane, to which 12 mmol triethylamine and 10 mg DMAP were added at 0° C. 10 mmol p-toluenesulfonyl chloride was added slowly. After the addition was completed, the reaction was maintained for 3 hours. The reaction mixture was quenched by adding water. Organic phase was dried and concentrated to give 3.7 g of Compound VI (wherein R₅ is trimethylsilyl).

¹H NMR (400 MHz, CDCl₃) δ 7.75-7.73 (m, 2H), 7.34-7.32 (m, 2H), 6.78-6.76 (m, 2H), 6.68(dd, 1H), 4.58 (d, 1H), 4.24 (s, 4H), 3.93 (dd, 1H), 3.71 (dd, 1H), 3.55-3.51 (m, 1H), 2.44 (s, 3H), 0.00 (s, 9H); ¹³C NMR (101 MHz, cdcl₃) δ 145.07, 143.56, 143.49, 133.13, 132.44, 129.88, 127.97, 119.43, 117.30, 115.32, 74.63, 68.37, 65.95, 64.29, 64.27, 26.89, −0.12.; HR-MS (ESI) calcd for C₂₁H₂₈O₆N₃SSi (M+H)⁺: 478.1468, found 478.1463.

Example 10 Preparation of (2R,3R)-2-azido-3-((tert-butyldimethylsilyl)oxy)-3-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)propyl 4-methylbenzenesulfonate (Compound VI, wherein R₅ is tert-butyldimethylsilyl)

9 mmol Compound V (wherein R₅ is teri-butyldimethylsilyl) was dissolved in 200 ml dichloromethane, to which 12 mmol triethylamine and 10 mg DMAP were added at 0° C. 10 mmol p-toluenesulfonyl chloride was added slowly. After the addition was completed, the reaction was maintained for 3 hours. The reaction mixture was quenched by adding water. Organic phase was dried and concentrated to give 4.2 g of Compound VI (wherein R₅ is tert-butyldimethylsilyl).

¹H NMR (400 MHz, CDCl₃) δ 7.75-7.69 (m, 2H), 7.48 (dq, 2H), 7.12 (dd, 1H), 6.95 (d, 1H), 6.90 (d, 1H), 4.74 (d, 1H), 4.28-4.17 (m, 5H), 3.96 (dd, 1H), 3.61 (q, 1H), 2.37 (d, 3H), 0.85 (s, 7H), −0.06 (s, 4H).; ¹³C NMR (101 MHz, CDCl₃) δ 143.59, 143 21, 143.16, 134.03, 133.24, 129.69, 128.09, 120.03, 114.38, 112.44, 76.17, 68.10, 66.52, 63.59, 63.56, 25.61, 21.53, 17.98, −4.80.; HR-MS (ESI) calcd for C₂₄H₃₃O₆N₃SSi (M+H)⁺: 519.1859, found 519.1866.

Example 11 Preparation of (2R,3R)-2-azido-3-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-hydroxypropyl 4-methylbenzenesulfonate (Compound VI, wherein R₅ is hydrogen)

9 mmol Compound XI (wherein R₅ is hydrogen) was dissolved in 200 ml dichloromethane, to which 12 mmol triethylamine and 10 mg DMAP were added at 0° C. 10 mmol p-toluenesulfonyl chloride was added slowly. After the addition was completed, the reaction was maintained for 3 hours. The reaction mixture was quenched by adding water. Organic phase was dried and concentrated to give 3.5 g of Compound VI (wherein R₅ is hydrogen).

¹H NMR (400 MHz, CDCl₃) δ 7.81 (d, J=8.4 Hz, 2H), 7.37 (d, J=8.4 Hz, 2H), 6.75-6.87 (m, 3H), 4.60 (d, J=6.4 Hz, 1H), 4.28 (s, 4H), 4.11 (dd, J=3.6 Hz, 10.4 Hz, 1H), 3.90 (dd, J=7.2 Hz, 10.4 Hz, 1H), 3.67-3.71 (m, 1H), 2.45 (s, 3H); ¹³C NMR (101 MHz, CDCl₃) δ 145.5, 144.2, 143.9, 132.1, 129.7, 128.3, 119.0, 117.9, 114.8, 73.1, 69.1, 65.7, 64.1; HR-MS (ESI) calcd for C₁₈H₂₀O₆N₃S (M+H)⁺: 406.1037, found 406.1035.

Example 12 Preparation of 1-((2R,3R)-2-azido-3(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3((trimethylsilyl)oxy)propyl)pyrrolidine (Compound VII, wherein R₅ is trimethylsilyl)

5 mmol Compound VI (wherein R₅ is trimethylsilyl) was dissolved in 50 ml DMF, to which 15 mmol pyrrolidine was added. The reaction was stirred at 60° C. for 10 hours. After the reaction was completed, water was added to quench the reaction, and the reaction mixture was extracted with ethyl acetate twice. The combined organic phases were washed with water, dried and concentrated to give 1.0 g of Compound VII (wherein R₅ is trimethylsilyl).

¹H NMR (400 MHz, CDCl₃) δ 6.82-5.74 (m, 3H), 4.60 (d, 1H), 4.23 (s, 4H), 3.44-3.39 (m, 1H), 2.52-2.41 (m, 5H), 2.33 (dd, 1H), 1.75-1.72 (m, 4H), 0.03 (s, 9H); ¹³C NMR (101 MHz, CDCl₃) δ 160.05, 139.96, 128.98, 128.47, 125.97, 72.29, 64.26, 64.19, 56.28, 54.07, 23.45, 21.74, 0.09.; HR-MS (ESI) calcd for C₁₈H₃₁O₃N₂Si (M+H)⁺: 376.1931, found 376.1940.

Example 13 Preparation of (1R,2R)-2-azido-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-(pyrrolidin-1-yl)propane-1-ol (Compound XII)

5 mmol Compound VI (wherein R₅ is hydrogen) was dissolved in 50 ml DMF, to which 15 mmol pyrrolidine was added. The reaction was stirred at 60° C. for 10 hours. After the reaction was completed, water was added to quench the reaction, and the reaction mixture was extracted with ethyl acetate twice. The combined organic phases were washed with water, dried and concentrated to give 1.1 g of Compound XII.

¹H NMR (400 MHz, CDCl₃) δ 6.82-6.92 (m, 3H), 4.93 (m, 1H), 4.24 (s, 4H), 4.10(m, 1H), 3.15-3.19 (m, 1H), 3.07 (m, 4H), 2.81-2.87 (m, 1H), 1.96 (m, 4H); ¹³C NMR (101 MHz, CDCl₃) δ 143.7, 134.1, 119.8, 117.5, 115.9, 75.5, 64.1, 63.9, 56.7, 54.4, 23.8; HR-MS (ESI) calcd for C₁₅H₂₁O₃N₄ (M+H)⁺: 305.1608, found 305.1611.

Example 14 Preparation of 1-((2R,3R)-2-azido-3-((tert-butyldimethylsilyl)oxy)-3-(2-dihydrobenzo[b][1,4]dioxin-6-yl)propyl)pyrrolidine (Compound XII)

5 mmol Compound VI (wherein R₅ is tert-butyldimethylsilyl) was dissolved in 50 ml DMF, to which 15 mmol pyrrolidine was added. The reaction was stirred al 60° C. for 10 hours. After the reaction was completed, water was added to quench the reaction, and the reaction mixture was extracted with ethyl acetate twice. The combined organic phases were washed with water, dried and concentrated to give 2.1 g of Compound XII.

¹H NMR (400 MHz, CDCl₃) δ 7.09-7.02 (m, 2H), 6.88 (d, 1H), 4.75-4.70 (m, 1H), 4.28-4.17 (m, 4H), 3.47 (q, 1H), 2.93-2.79 (m, 4H), 2.53 (dd, 1H), 2.02 (dd, 1H), 1.84 (hept, 4H), 0.84 (s, 7H), 0.02 (s, 4H).; ¹³C NMR (101 MHz, CDCl₃) δ 143.18, 143.15, 132.60, 120.03, 114.34, 112.38, 78.23, 63.80, 63.78, 63.69, 59.99, 54.51, 25.61, 23.73, 18.03, −4.78.; HR-MS (ESI) calcd for C₂₁H₃₄O₃Si (M+H)⁺: 418.2400, found 418.2413.

Example 15 Preparation of (1R,2R)-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-(pyrrolidin-1-yl)-1-((trimethylsilyl)oxy)propan-2-amine (Compound VIII, wherein R₅ is trimethylsilyl)

4 mmol Compound VII (wherein R₅ is trimethylsilyl) was dissolved in 200 ml methanol, to which 20 mg of 5% Pd/C was added. The reaction was carried out under 0.1 MPa of hydrogen pressure at 25° C. for 10 hours. After the reaction was completed, the reaction mixture was filtrated and concentrated to give 1.3 g of Compound VIII (wherein R₅ is trimethylsilyl).

¹H NMR (400 MHz, CDCl₃) δ 7.15-7.10 (m, 1H), 7.07-7.00 (m, 1H), 6.88 (d, 1H), 4.46 (d, 1H), 4.28-4.17 (m, 4H), 3.59 (d, 2H), 3.25 (qt, 1H), 2.91-2.77 (m, 4H), 2.49 (dd, 1H), 2.40 (dd, 1H), 1.89- 1.80 (m, 4H), 0.16 (s, 7H).; ¹³C NMR (101 MHz, CDCl₃) δ 143.16, 142.99, 134.17, 120.00, 114.33, 112.41, 78.06, 63.52, 63.50, 61.58, 54.57, 53.62, 23.64, −0.26.; HR-MS (ESI) calcd for C₁₈H₃₀O₃N₂SI (M+H)⁺: 350.2026. found 350.2032.

Example 16 Preparation of (1R,2R)-2-amino-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-(pyrrolidin-1-yl)propane-1-ol (Compound VIII, wherein R₅ is hydrogen)

2 mmol Compound XII (wherein R₅ is hydrogen) was dissolved in 100 ml methanol, to which 10 mg of 5% Pd/C was added. The reaction was carried out under 0.1 MPa of hydrogen pressure at 25° C. for 10 hours. After the reaction was completed, the reaction mixture was filtrated and concentrated to give 0.6 g of Compound VIII (wherein R₅ is hydrogen).

¹H NMR (400 MHz, CDCl₃) δ 6.77-6.85 (m, 3H), 5.85 (d, J=7.2 Hz, 1H), 4.91 (d, J=3.6 Hz, 1H), 4.23 (s, 4H), 4.15-4.21 (m, 1H), 2.74-2.83 (m, 2H), 2.61-2.67 (m, 4H), 2.07-2.11 (m, 2H), 1.79-1.81 (m, 4H), 1.51-1.56 (m, 2H), 1.22-1.33 (m, 10H). 0.89 (t, J=6.8 Hz, 3H); ¹³C NMR (101 MHz, CDCl₃) δ 174.1, 143.2, 142.7, 134.6, 119.2, 117.3, 115.1, 75.6, 64.5, 57.9, 55.1, 52.0, 36.5, 31.7, 29.5, 29.1, 25.8, 23.4, 22.7, 13.9. HR-MS (ESI) calcd for C₂₃H₃₇O₄N₂ (M+H)⁺: 405.2748, found 405.2741.

Example 16a Preparation of Crystal Form A of (1R,2R)-2-amino-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-(pyrrolidin-1-yl)propane-1-ol:

Preparation of 5% NaOH solution: add 10 g sodium hydroxide to 190 g water, dissolve, and store the solution until use.

In a clean and dry 1000 ml reaction bottle, 100 g ELG-4-PTA and 200 g drinking water were added, and the 5% NaOH solution prepared in advance was added under stirring. The resulting solution was stirred adequately for 0.5 h and different layers were formed. The organic layer was washed with 200 g drinking water, and the layers were separated to obtain the organic layer, to which 10 g triethylamine and 6 g Pd/C were added. The reaction was performed at controlled temperature of 20 to 30° C. and at pressure of 0.3 to 0.5 Mpa for 12-18 hours. After the reaction was completed, the reaction atmosphere was replaced with nitrogen gas, then the mixture was warmed to 35-40 ° C., dissolved, filtered to yield filtrate. The filtrate was concentrated to about 240 g of the solution of ELG-5 in isopropyl acetate under reduced pressure while controlling the external temperature as ≤45° C. To the solution 17 g drinking water was added. The resulting solution was stirred to precipitate crystal, the temperature was reduced to −5 to 5° C. and maintained for 2 hours to crystallize. The resulting mixture was filtered, rinsed with hexane, and dried under reduced pressure at controlled external temperature of ≤40° C. to give 55 g to 65 g white solid (as monohydrate).

1. X-ray Diffraction Measurement of Crystal Form A:

TABLE 1 Instruments of X-ray diffraction and the corresponding parameters Instrument name X-ray Diffractometer (XRD) Instrument type Germany, Bruker D8 advance Instrument Catalog No. LY-01-005 Light source Cu Method and parameter Voltage and current 40 kV, 40 mA Starting and ending positions 3-40° 2θ stepping 0.02° 2θ Time for each stepping 0.5 s

The result showed that the crystal form A has a X-ray powder diffraction pattern having the characteristic diffraction peaks at 2-theta angle (°): 17.5, 18.5, and 21.3.

In particular, the crystal form A has a X-ray powder diffraction pattern having the characteristic diffraction peaks at 2-theta angle (°): 17.5, 18.5, 19.9, 21.3, and 25.7.

More particularly, the crystal form A has a X-ray powder diffraction pattern having the characteristic diffraction peaks at 2-theta angle (°): 6.4, 11.4, 12.3, 17.5, 18.5, 19.9, 21.3, 22.9, 24.1, and 25.7.

The results of X-ray diffraction experiment of the crystal form A were shown in FIGS. 1 and 2.

2. Thermogravimetric Analysis (TGA) of the Crystal Form A

TABLE 2 Instruments of TGA and the corresponding parameters Instrument name Thermogravimetric analyser (TGA) Instrument type TA Q500 Instrument Catalog No. LY-01-003 Method and parameter 1. Raising the temperature to 300.0° C. in a rate of 10.0° C./min 2. N₂ flowing rate of 40 mL/min

TGA showed that the crystal lost about 6.0% of total weight progressively before 100° C., the temperature at which the solvent was removed was about 50° C., and the sample was decomposed after 150° C.

The result of TGA experiment of the crystal form A was shown in FIG. 3.

3. Differential Scanning Calorimetry (DSC) Experiment of the Crystal Form A

TABLE 3 Instruments of DSC and the corresponding parameters Instrument name Differential scanning calorimeter (DSC) Instrument type TA Q200 Instrument Catalog No. LY-01-002 Method and parameter 1. Equilibrating at 20.0° C. 2. Raising the temperature to 200.0° C. in a rate of 10.0° C./min 3. N₂ flowing rate of 40 mL/min 4. Aluminum pan with lid.

DSC showed that the sample has an endothermal peak between 68° C. and 91° C., the onset value of the endothermal peak is 82.9° C. and the peak value is 85.9° C. The result of DSC experiment of the crystal form A was shown in FIG. 4.

Example 17 Preparation of (1R,2R)-1-((tert-butyldimethylsilyl)oxy)-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-(pyrrolidin-1-yl)propan-2-amine (Compound VIII, wherein R₅ is tert-butyldimethylsilyl)

2 mmol Compound XII (wherein R₅ is tert-butyldimethylsilyl) was dissolved in 100 ml methanol, to which 10 mg of 5% Pd/C was added. The reaction was carried out under 0.1 MPa of hydrogen pressure at 25° C. for 10 hours. After the reaction was completed, the reaction mixture was filtrated and concentrated to give 1.1 g of Compound VIII (wherein R₅ is tert-butyldimethylsilyl).

¹H NMR (400 MHz, CDCl₃) δ 7.14-7.09 (m, 1H), 7.03 (dd, 1H), 6.88 (d, 1H), 4.67 (dt, 1H), 4.28-4.17 (m, 4H), 3.59 (d, 2H), 3.24 (qt, 1H), 2.92-2.77 (m, 4H), 2.74 (dd, 1H) 2.40 (dd, 1H), 1.89-1.80 (m, 4H), 0.84 (s, 7H), 0.01 (s, 4H).; ¹³C NMR (101 MHz, CDCl₃) δ 143.17, 143.04, 134.13, 120.03, 114.33, 112.46, 76.86, 63.55, 63.52, 61.53, 54.58, 53.69, 25.61, 23.74, 17.89, −4.79.; HR-MS (ESI) calcd for C₂₁H₃₆O₃N₂Si (M+H)⁺: 392.2495, found 392.2483.

Example 18 Preparation of N-((1R,2R)-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-1-((trimethylsilyl)oxy)-3-(pyrrolidin-1-yl)propan-2-yl)octanamide (Compound X, wherein R₅ is trimethylsilyl)

1 mmol Compound VIII (wherein R₅ is trimethylsilyl) was dissolved in 30 ml DMF, to which 1.5 mmol DIPEA and 1.2 mmol Compound IX (wherein R₆ is succimidyloxy) were added. After the addition was completed, the reaction was maintained at 25° C. for 24 hours. After the reaction was completed, water was added to quench the reaction, and the reaction mixture was extracted with ethyl acetate twice. The combined organic phases were washed with water, dried and concentrated to give 0.5 g of Compound X.

¹H NMR (400 MHz, CDCl₃) δ 6.76-6.59 (m, 3H), 5.77 (d, 1H), 5.01 (d, 1H), 4.16 (s, 3H), 4.06 (q, 1H), 3.99 (dd, 1H), 2.63 (dd, 1H), 2.58-2.38 (m, 4H), 2.24 (dd, 1H). 2.03 (td, 2H), 1.98 (S, 1H), 1.76-1.64 (m, 4H), 1.45 (p, 2H), 1.27-1.09 (m, 8H), 0.82 (t, 3H).; ¹³C NMR (101 MHz, CDCl₃) δ 172.55, 171.02, 142.91, 142.34, 135.90, 118.63, 116.57, 114.67, 71.33, 64.26, 64.18, 60.31, 56.47, 55.06, 54.26, 53.94, 36.76, 31.61, 29.03, 29.01, 25.64, 23.59, 22.59, 20.97, 14.14, 14.05, 1.36.; HR-MS (ESI) calcd for C₁₈H₃₁O₃N₂Si (M+H)⁺: 477.3149. found 477.3155.

Example 19 Preparation of N-((1R,2R)-1-((tert-butyldimethylsilyl)oxy-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-(pyrrolidin-1-yl)propan-2-yl)octanamide (Compound X, wherein R₅ is tert-butyldimethylsilyl)

1 mmol Compound VIII (wherein R₅ is tert-butyldimethylsilyl) was dissolved in 30 ml DMF, to which 1.5 mmol DIPEA and 1.2 mmol Compound IX (wherein R₆ is succimidyloxy) were added. After the addition was completed, the reaction was maintained at 25° C. for 24 hours. After the reaction was completed, water was added to quench the reaction, and the reaction mixture was extracted with ethyl acetate twice. The combined organic phases were washed with water, dried and concentrated to give 0.9 g of Compound X.

¹H NMR (400 MHz, CDCl₃) δ 7.04 (ddd, 1H), 6.91-6.81 (m, 2H), 6.18 (d, 1H). 5.19 (d, 1H), 4.28-4.17 (m, 4H), 4.11 (dq. 1H), 2.91-2.83 (m, 2H), 2.86-2.76 (m, 2H), 2.59 (dd, 1H), 2.51 (dd, 1H), 2.26 (dt, 1H), 2.19 (dt, 1H), 1.83 (p, 4H), 1.63 (dt, 1H), 1.47 (dt, 1H), 1.39-1.14 (m, 7H), 0.94-0.84 (m, 3H), 0.85 (s, 6H), −0.06 (s, 4H).; ¹³C NMR (101 MHz, CDCl₃)δ 174.41, 143.16, 143.13, 134.01, 120.36, 114.37, 112.72, 76.42, 63.59, 63.56, 60.11, 54.61, 54.20, 35.54, 31.26, 28.68, 28.40, 25.62, 25.07, 23.79, 22.79, 17.98, 14.06, −4.76.; HR-MS (ESI) calcd for C₂₉H₅₀O₄N₂Si (M+H)⁺: 518.3540, found 518.3549.

Example 20 Preparation of Eliglustat

1 mmol Compound VIII (wherein R₅ is hydrogen) was dissolved in 30 ml DMF, to which 1.5 mmol DIPEA and 1.2 mmol Compound IX (wherein R₆ is succimidyloxy) were added. After the addition was completed, the reaction was maintained at 25° C. for 24 hours. After the reaction was completed, water was added to quench the reaction, and the reaction mixture was extracted with ethyl acetate twice. The combined organic phases were washed with water, dried and concentrated to give 0.3 g Eliglustat.

¹H NMR (400 MHz, CDCl₃) δ 6.72-6.90 (m, 3H), 5.83 (d, 1H), 4.89 (d, 1H), 4.25 (m, 4H), 4.15-4.19 (m, 1H), 2.71-2.77 (m, 2H), 2.56-2.70 (m, 4H) , 2.10 (t, 2H), 1.73-1.82 (m, 4H), 1.46-1.57 (m, 2H), 1.15-1.30 (m, 8H), 0.88 (t, 3H); ¹³C NMR (101 MHz, CDCl₃) δ 174.47, 143.25, 143.17, 135.21, 120.41, 114.34, 112.85, 74.96, 63.81, 63.60, 59.47, 54.48, 53.67, 35.86, 31.39, 28.44, 28.27, 25.39, 23.75, 22.71, 14.08. HR-MS (ESI) calcd for C₂₃H₃₇O₂N₄ (M+H)⁺: 405.2753. found 405.2760.

Example 21 Preparation of Eliglustat

1 mmol Compound X (wherein R₅ is trimethylsilyl) was dissolved in 30 ml THF, to which 20 ml of 2N HCl was added. After the addition was completed, the reaction was maintained at 25° C. for 2 hours. After the reaction was completed, water was added to quench the reaction, and the reaction mixture was extracted with ethyl acetate twice. Organic phases were combined, and washed with saturated sodium bicarbonate solution once. The resulting organic phase was dried and concentrated to give 0.4 g Eliglustat.

¹H NMR (400 MHz, CDCl₃) δ 6.72-6.90 (m, 3H), 5.83 (d, 1H), 4.89 (d, 1H), 4.25 (m, 4H), 4.15-4.19 (m, 1H), 2.71-2.77 (m, 2H), 2.56-2.70 (m, 4H), 2.10 (t, 2H), 1.73-1.82 (m, 4H), 1.46-1.57 (m, 2H), 1.15-1.30 (m, 8H), 0.88 (t, 3H); ¹³C NMR (101 MHz, CDCl₃) δ 174.47, 143.25, 143.17, 135.21, 120.41, 114.34, 112.85, 74.96, 63.81, 63.60, 50.47, 54.48, 53.67, 35.86, 31.39, 28.44, 28.27, 25.39, 23.75, 22.71, 14.08. HR-MS (ESI) calcd for C₂₃H₃₇O₂N₄ (M+H)⁺: 405.2753, found 405.2760. 

1-50. (canceled)
 51. A process for preparation of Eliglustat and pharmaceutically acceptable salts thereof,

the process comprising the following steps: (a-1) sulfonylation reaction of Compound V to give Compound VI,

wherein R₅ is hydrogen or hydroxy-protecting group, said hydroxy-protecting group is selected from alkyl, haloalkyl, aralkyl, alkoxyalkyl, allyl, acyl or silyl protective group, such as t-BuMe₂Si, t-BuPh₂Si, (i-Pr)₃Si, Et₃Si, Me₃Si, allyl, 2-tetrahydropyranyl, methoxymethyl, formyl, acetyl, benzyl or —CH₂Ar, wherein Ar is unsubstituted or substituted aryl, such as p-methoxyphenyl or halogen-substituted phenyl, M is alkyl, aryl, substituted aryl or substituted alkyl, (a-2) reacting Compound VI with pyrrolidine to give Compound VII,

(a-3) reducing Compound VII by catalytic hydrogenation with metal catalyst or reducing Compound VII with organophosphorus reagent, to give Compound VIII,

(a-4) amidation reaction of Compound VIII with Compound IX to give Compound X,

wherein R₆ is selected from hydroxy, halogen or succimidyloxy, when R₅ is hydrogen, Compound X is Eliglustat, or when R₅ is hydroxy-protecting group, the following step is further carried out: (a-5) deprotecting Compound X to remove hydroxy-protecting group, to give Eliglustat


52. The process according to claim 51, wherein R₅ is hydrogen or silyl protective group.
 53. The process according to claim 51, wherein R₆ is chloro or succimidyloxy.
 54. The process according to claim 51, wherein in the step (a-1), the sulfonylation reaction is carried out with sulfonyl halide, such as alkylsulfonyl chloride, arylsulfonyl chloride, substituted arylsulfonyl chloride or substituted alkylsulfonyl chloride, the reaction can be carried out without catalyst or with appropriate amount of acylation catalyst, and the catalyst used may be DMAP; the base is an organic base.
 54. The process according to claim 51, wherein in the step (a-2), pyrrolidine is reacted with the sulfonate of formula VI, and the reaction solvent is an organic aprotic solvent or solvents.
 56. The process according to claim 51, wherein in the step (a-3), the metal catalyst used in the hydrogenation is Pd catalyst or Ni catalyst and the organophosphorus reagent is triphenylphosphine.
 57. The process according to claim 51, wherein in the step (a-4): when R₆ is hydroxy, the reaction of Compound VIII with Compound IX is carried out under catalysis of coupling agent to give Compound X; and the coupling agent is a coupling agent or agents for amidation; or when R₆ is chloro or succimidyloxy, amidation reaction of Compound VIII with Compound IX yields Compound X; the reaction is carried out without catalyst or with an appropriate amount of deacid reagent.
 58. The process according to claim 51, wherein in the step (a-5), the reaction conditions are: when R₅ is silyl protective group, the reaction of step a-5 is carried out in the presence of base, acid or a fluorine-containing salt, the base is selected from alkali metal or alkaline earth metal hydroxide or carbonate, and the fluorine-containing salt is tetrabutylammonium fluoride (TBAF); when R₅ is alkyl, haloalkyl, alkoxyalkyl or allyl protective group, the reaction of step a-5 is carried out in the presence of an acid; when R₅ is aralkyl protective group, the reaction of step a-5 is carried out under catalytic hydrogenation with a Pd catalyst or Ni catalyst; and the organophosphorus reagent is triphenylphosphine; when R₅ is p-methoxybenzyl, the reaction of step a-5 is carried out in the presence of an oxidizing agent; or when R₅ is acyl protective group, the reaction of step a-5 is carried out under the condition of conventional deprotection to remove the acyl.
 59. The process according to claim 51, wherein R₅ is hydrogen, and the process only includes the above reaction steps (a-1), (a-2), (a-3) and (a-4).
 60. The process according to claim 51, wherein the process comprises the following steps before step (a-3): (c-1) coupling reaction of Compound I with Compound II in the presence of Lewis acid, deacid reagent and coordination agent, to give Compound III,

wherein each of R₁, R₂ and R₄, independent of each other, is selected from hydrogen, alkyl, aryl or aralkyl, such as phenyl, isopropyl or benzyl, (c-2) optionally, reacting Compound III with hydroxy-protecting reagent in the presence of base to give Compound IV,

wherein R₅ is hydroxy-protecting group, said hydroxy-protecting group is selected from alkyl, haloalkyl, aralkyl, alkoxyalkyl, allyl, acyl or silyl protective group, such as t-BuMe₂Si, t-BuPh₂Si, (i-Pr)₃Si, Et₃Si, Me₃Si, allyl, 2-tetrahydropyranyl, methoxymethyl, formyl, acetyl, benzyl or —CH₂Ar, wherein Ar is unsubstituted or substituted aryl, such as p-methoxyphenyl or halogen-substituted phenyl; and (c-3) preparing the compound of formula V by the following steps: (c-3.1) reducing Compound III to obtain the Compound V wherein R₅ is hydrogen

or reducing Compound IV to obtain the Compound V wherein R₅ is hydroxy-protecting group as defined above

or (c-3.2) oxidizing Compound III to give Compound XI-1, and reducing Compound XI-1 to obtain the Compound V wherein R₅ is hydrogen (i.e, Compound XI)

or oxidizing Compound IV to give Compound V-1, and reducing Compound V-1 to obtain the Compound V wherein R₅ is hydroxy-protecting group as defined above


61. The process according to claim 60, wherein R₄ is isopropyl and R₁ and R₂ are phenyl.
 62. The process according to claim 60, wherein R₆ is chloro or succimidyloxy.
 63. The process according to claim 60, wherein R₅ is hydrogen or silyl protective group.
 64. The process according to claim 60, wherein: In step c-1, the Lewis acid is titanium tetrachloride or tin dichloride, the deacid reagent is organic base, and the coordination agent is N-methyl pyrrolidone; In the optional step c-2, the reaction solvent is an organic aprotic solvent or solvents; In step c-3.1, the reducing agent is selected from sodium borohydride, potassium borohydride, boron trifluoride etherate, boranes, or a mixture of any two or more thereof; In step c-3.2, the oxidizing agent is peroxide or a manganese-containing salt or salts, the reaction is carried out with or without catalysis of a base selected from alkali metal or alkaline earth metal hydroxide or carbonate; In step c-3.2, the reducing agent is selected from sodium borohydride, potassium borohydride, boron trifluoride etherate, boranes, or a mixture of any two or more thereof.
 65. A process for preparation of the compound of formula IV,

wherein R₅ is hydroxy-protecting group, said hydroxy-protecting group is selected from alkyl, haloalkyl, aralkyl, alkoxyalkyl, allyl, acyl or silyl protective group, wherein Ar is unsubstituted or substituted aryl, the process comprising the following steps: (c-1) coupling reaction of Compound I with Compound II in the presence of Lewis acid, deacid reagent and coordination agent, to give Compound III,

and (c-2) reacting compound III with hydroxy-protecting reagent in the presence of base to give Compound IV

wherein each of R₁, R₂ and R₄, independent of each other, is selected from hydrogen, alkyl, aryl or aralkyl.
 66. The process according to claim 65, wherein R₁ and R₂ are hydrogen and R₄ is phenyl or benzyl.
 67. The process according to claim 65, wherein R₄ is isopropyl and R₁ and R₂ are phenyl.
 68. The process according to claim 65, wherein the reaction conditions are: In step c-1, the Lewis acid is titanium tetrachloride or tin dichloride, the deacid reagent is organic base, In step c-2, the reaction solvent is an organic aprotic solvent or solvents.
 68. Crystal form A of (1R,2R)-2-amino-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-(pyrrolidin-1-yl)propane-1-ol monohydrate, wherein the crystal form A has a X-ray powder diffraction pattern having characteristic diffraction peaks at 2-theta angle (°): 17.5, 18.5, and 21.3.
 70. The crystal form A according to claim 65, wherein the crystal form A has a X-ray powder diffraction pattern having the characteristic diffraction peaks at 2-theta angle (°): 17.5, 18.5, 19.9, 21.3, and 25.7. 